1: oxalyl chloride, pyridine / benzene / 6 h / Ambient temperature 2: pyridine, 4-(dimethylamino)pyridine / CH2Cl2 / 6 h / Ambient temperature 3: 90.5 percent / ZnCl2, K / tetrahydrofuran / 1) room temp., 1 h, 2) 40-50 degC, 1 h 4: 10 percent / tetrahydrofuran / 1) -78 degC, 2) -20 degC, 30 min View Scheme

ozone in various solvent(s) T=-78°C;

1: 78.6 percent / AgNO3, 8percent KOH / ethanol; H2O / 2 h / 0 °C 2: 1) O3, 2) Me2S / 1) CH2Cl2, -78 degC, 2) room temp., 1 h View Scheme

1: 1.) piperidine; 2.) AcOH / 1.) Et2O; 2.) Et2O 2: Ag2O 3: O3 / various solvent(s) / -78 °C View Scheme